Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2018-2019  Made to Order Software Corp.  All Rights Reserved
       3             :  *
       4             :  * https://snapwebsites.org/
       5             :  * contact@m2osw.com
       6             :  *
       7             :  * This program is free software; you can redistribute it and/or modify
       8             :  * it under the terms of the GNU General Public License as published by
       9             :  * the Free Software Foundation; either version 2 of the License, or
      10             :  * (at your option) any later version.
      11             :  *
      12             :  * This program is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      15             :  * GNU General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU General Public License along
      18             :  * with this program; if not, write to the Free Software Foundation, Inc.,
      19             :  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
      20             :  */
      21             : 
      22             : /** \file
      23             :  * \brief Verify that the log2() function.
      24             :  *
      25             :  * This file implements test for the log2() function.
      26             :  */
      27             : 
      28             : // self
      29             : //
      30             : #include "main.h"
      31             : 
      32             : 
      33             : 
      34             : // snapdev lib
      35             : //
      36             : #include "snapdev/log2.h"
      37             : 
      38             : 
      39             : 
      40             : 
      41             : 
      42           4 : CATCH_TEST_CASE("log2", "[math]")
      43             : {
      44           4 :     CATCH_START_SECTION("powers of 2")
      45             :     {
      46          65 :         for(int i = 0; i < 64; ++i)
      47             :         {
      48          64 :             std::uint64_t v = 1ULL << i;
      49          64 :             CATCH_REQUIRE(snap::log2(v) == i);
      50             :         }
      51             :     }
      52             :     CATCH_END_SECTION()
      53             : 
      54           4 :     CATCH_START_SECTION("random numbers")
      55             :     {
      56          65 :         for(int i = 0; i < 64; ++i)
      57             :         {
      58          64 :             std::uint64_t r = (static_cast<std::uint64_t>(rand()) << 32) ^ static_cast<std::uint64_t>(rand());
      59          64 :             r &= (1ULL << i) - 1ULL;
      60          64 :             std::uint64_t v = (1ULL << i) | r;
      61             : 
      62             :             // same difference, all the lower bits are ignored in the
      63             :             // computation
      64             :             //
      65          64 :             CATCH_REQUIRE(snap::log2(v) == i);
      66             :         }
      67             :     }
      68             :     CATCH_END_SECTION()
      69           8 : }
      70             : 
      71             : 
      72             : 
      73             : // vim: ts=4 sw=4 et